What you are programming is the graph of how these machines connect and flow data(keypunch cards) through each other, while the machines themselves and their function are abstracted out. Data does not stay "at rest", it's presumed to reach a terminating point where it exits the graph. A buildup of unprocessed data in a machine's inbox results in an overflow.
It's a very useful model for making a debuggable asynchronous system since it imposes static constraints everywhere that you can map to your real hardware resources, versus the emphasis on dynamism seen in the actor model(actors hold private data, modify their state, create new actors - all explicitly disallowed in FBP).
https://en.m.wikipedia.org/wiki/Unit_record_equipment
What you are programming is the graph of how these machines connect and flow data(keypunch cards) through each other, while the machines themselves and their function are abstracted out. Data does not stay "at rest", it's presumed to reach a terminating point where it exits the graph. A buildup of unprocessed data in a machine's inbox results in an overflow.
It's a very useful model for making a debuggable asynchronous system since it imposes static constraints everywhere that you can map to your real hardware resources, versus the emphasis on dynamism seen in the actor model(actors hold private data, modify their state, create new actors - all explicitly disallowed in FBP).